Injury to the male urethra below the perineal membrane causes urine to accumulate in –
💡 Explanation
## **Core Concept**
The male urethra is divided into four parts: preprostatic, prostatic, membranous, and spongy (penile). The **perineal membrane** (also known as the triangular ligament) separates the membranous urethra from the spongy urethra. Injury to the urethra below this membrane affects the spongy urethra.
## **Why the Correct Answer is Right**
Injury to the male urethra below the perineal membrane involves the spongy urethra, which is surrounded by the corpus spongiosum. Damage here causes urine to accumulate in the **superficial perineal pouch**, also known as **Colles' space**. This space is a fascial compartment that contains the bulb of the penis, the crura, and the associated muscles and vessels.
## **Why Each Wrong Option is Incorrect**
* **Option A:** The **deep perineal pouch** contains structures like the membranous urethra, bulbourethral glands, and the internal urethral sphincter. Injury above the perineal membrane would affect this space, not below.
* **Option B:** The **penile urethra** itself isn't a space where urine accumulates due to injury; it's part of the urethra.
* **Option D:** The **pelvic cavity** is a large space containing pelvic organs; urethral injury below the perineal membrane wouldn't directly cause urine accumulation here.
## **Clinical Pearl / High-Yield Fact**
A key point to remember is that urethral injuries can lead to **urine extravasation**. In the case of an injury below the perineal membrane, urine can accumulate in **Colles' space**, leading to swelling in the perineum and potentially tracking along fascial planes.